Learn Hardcore Russian: На почте длинная очередь у кассы. - At the post office there is a long line at the cashier’s.

In Russian the present‐tense copula is usually omitted in simple descriptive statements. You can include есть for emphasis (На почте есть длинная очередь у кассы), but it’s often dropped. Similarly, to focus on the action you could say На почте у кассы стоит длинная очередь, but the verb isn’t required for the basic meaning.

What case is почте in and why?

Почте is in the prepositional case because of the preposition на when used to indicate location. When talking about being at an institution or surface in Russian, you typically use на + prepositional (e.g. на почте, на заводе, на станции).

What case is кассы in and why is у used here?

Кассы is in the genitive case because preposition у always takes genitive. У кассы literally means “by the cashier’s window” or “at the cashier’s desk,” indicating proximity or possession (i.e. “at the place of the cashier”).

Why is the noun phrase длинная очередь in the nominative case, and why does длинная end with -ая?

Длинная очередь is the subject of this verbless clause, so both adjective and noun are in the nominative singular. The ending -ая on длинная agrees in gender (feminine), number (singular), and case (nominative) with очередь, which is a feminine noun.

Is the word order fixed? Could I say У кассы длинная очередь на почте?

Russian word order is fairly flexible for emphasis. The neutral word order is На почте у кассы длинная очередь, but you can front У кассы to highlight the precise spot, or lead with Длинная очередь to stress its length. Just remember that prepositional phrases setting the scene often come first.

Why do we say на почте and not в почте or в почтовом отделении?

The noun почта meaning “post office” commonly pairs with на + prepositional case for location (на почте). В почтовом отделении (“in the postal branch/office”) is also correct but more formal. Saying в почте by itself would be odd, since почта can also mean “mail.”

What’s the difference between у кассы, к кассе, and в кассу?

• у кассы (genitive with у) indicates static location: “by the cashier’s desk.”
• к кассе (dative with к) expresses motion toward a point: “toward the cashier.”
• в кассу (accusative with в) denotes motion into the cashier’s window/area: “into the cashier’s desk.”

How can I add a verb to express that the line is standing?

Use the verb стоять (“to stand”):
На почте у кассы стоит длинная очередь.
Here “стоит” is the third‐person singular of стоять. You can also vary the word order for style: На почте стоит длинная очередь у кассы.